Electric dry battery



- 22,395@ G. H. wnLmNsoN M9527 y ELETRIjc DRY BATTERY Filed March. 20.194'? .i 555" H15 ,3 j@ /3 if /4 Invenor: y

7 /umr/W Ge orge Henry Wil/(i no n R770' By// Attorney.l

Patented Aug. 22, 1950 ELECTRIC DRY BATTERY George Henry Wilkinson,Harlington, England,

assgnor to Electric & Musical Industries Limited, Hayes, England, acompany of Great Britain Application March 20, 1947, Serial No. 735,950In Great Britain March 19, 1942 Section 1, Public Law 690, August 8,1946 Patent expires March 19, 1962 11 Claims. (Cl. 136-111) Thisinvention relates to'electric dry batteries of the kind comprising aplurality of substantially flat cells, each cell comprising a number ofelements namely a positive and negative electrode, a depolarising agentand an electrolyte, these cell elements being .superimposed in propersequence y and the cells so formed being arranged face-toface to form abattery.

In batteries of this kind it is important to ensure that creepage of theelectrolyte of one cell to another cell is prevented or reduced to aminimum and various proposals have heretofore been made for thispurpose. y

The object of the present invention is to provide an improved battery inwhich effective steps are taken to guard against the creeping ofelectrolyte from one cell to another but in which the necessity forseparately sheathed cells is avoided, so facilitating manufacture.

According to one feature of the present invention an electric drybattery of the kind referred to is provided in which a plurality ofelectrolyte cell elements or a Aplurality of groups of cell elements,each group containing an electrolyte element, are arranged in a commonsheath of flexible electrolyte-resisting dielectric material, saidsheath being perforated and so applied to said plurality of cellelements or groups as to form separate compartments Within each of whichone 'of said cell elements or groups is enclosed with portions of thefaces of said cell elements or groups exposed through lateralperforations in the sides of the compartments and said cell elements orgroups are held together under pressure so that said sheath prevents orsubstantially reduces the escape of electrolyte'from one cell to anotherwhilst electrical contact between adjacent cells is obtained throughsaid perforations.

According to a further feature of the invention a method of making anelectric dry battery of the kind referred to is provided in which saidsheath is folded so as to bring said cell elements or groups intocooperative relationship with the aid if necessary of further cellelements so as to form a battery of cells and then securing said cellstogetherunder pressure.

According to a further feature of the invention a method of making anelectric dry battery of the kind referred to is provided in which thecell elements or groups are arranged edge to edge but f spaced apartwith portions of the faces of said cell elements or groups exposedthrough lateral perforations in the sheath compartments, then securingthe opposite surfaces of said sheath together at the spaces between`lsaid cell elements or groups so as to form separate compartmentswithin which the said cell elements or groups are separately enclosed.

According to another feature of the invention a method of making anelectric dry battery of the kind referred to is provided which comprisesapplying the plurality of spaced electrolyte cell elements or aplurality of spaced groups of cell elements to the perforated strip sothat one face of each of said elements or groups is exposed through oneof the perforations, then folding said strip so that its longitudinaledges overlap one another on the opposite faces of each of said elementsor groups so that the other faces are also exposed through perforations,and lthen securing together opposite surfaces of said strip which liebetween adjacent edges of said cell elements or groups so as to encloseeach of said cell elements or groups in a separate compartment.

According to yet another feature of the invention a method of makingelectric dry batteries of the kind referred to in a continuous manner isprovided which comprises severing a plurality of said cell elements orgroups arranged in said common sheath and arranging them to form abattery with the aid, if necessary, of further cell elements.

The cell elements or groups can conveniently be assembled to formabattery by folding said sheath at the opposite surfaces which aresecured together so that the cell elements or groups assume a zigzagformation, the elements or groups i being then pressed together toprovide the neces- The assembled battery sary electrical contact. maythen be bound to hold the elements in the desired relationship underpressure and then the bound battery may be coated with or dipped in waxor some other moisture-resisting material, such as rubber solution.

It is not necessary that the cell elements provided in the separatecompartments should constitute in themselves individual cells since, insome cases, it may be preferred, for example, to arrange thedepolarising element which may be in the form of a flat tablet and theelectrolyte element which may comprise a piece of gauze impregnated withan appropriate electrolyte in the same compartment, and the necessarypositive and negative electrodes may be insertedin the appropriatepositions during assembly to form the battery. Preferably, however, eachcompartment contains four elements, the positive and negative electrodesbeing of a composite construction comprising a plate of zinc with anadneiging @Outing of carbon. Other methods of grouping the cell elementsmay, if desired, be

employed.

In order that the invention may be clearly understood and readilycarried into effect, it will now be more fully described with referenceto the accompanying drawings which illustrate several embodiments of theinvention, in which- Figure 1 is a plan view of a portion of saidmaterial with cell elements or groups arranged in positionrprior toforming the sheath,

Figure 2 illustrates the cell elements or groups after one stage of thesheathing operation,

Figure 3 is a cross-section on an enlarged scale taken along the line3-3 of Figure 2,

Figure 4 illustrates the cell elements or groups after completing thesheathing operation,

Figure 5 is a view on an enlarged scale illustrating the method ofassembling the cell elements or groups to form a battery.

Figure 6 is a perspective view illustrating the completed cell assembly,

Figures "l, 8 and 9 are views similar to Figures 1, 2 and 5 illustratinga further embodiment of the invention,

Figure 10 is a cross-sectionalview illustrating a further embodiment ofthe invention,

Figure 1l is a cross-section similar to Figure 3 but showing a modiiledform of carbon-zinc element,

Figures 12 and 13 illustrate different methods of assembling the cellelements or groups, and

Figure 14 shows a sheath formed of two overlapping strips.

The two embodiments of the invention shown in Figures 1 to 9 illustratethe invention as applied to the manufacture of batteries in which groupsof cell elements are arranged in separate compartments in a commonsheath, each group forming an individual cell.

Referring first to Figures 1 to 6 of the drawings, each cell is composedof four cell elements comprising a rectangular tablet I I ofdepolarising material having on one side a protuberance I 2 and adjacentthe side of the tablet II opposite the protuberance I2 is a gauze pad I3impregnated with a suitable electrolyte solution and having a thin layerof electrolyte paste I 4 which is in intimate contact with the zincsurface of a composite carbon-zinc element which comprises a zinc plateI5 .having an adhering coating of carbon I6. The zinc plate I5preferably has rounded corners as shown in Figure 1. The common sheathfor the cells is made from a strip I1 of exible electrolyte-resistingdielectric sheet material which is provided with two longitudinal rowsof perforations I3 and I9 arranged in the manner shown. The cells areapplied over the row of perforations I9 as shown in Figure 1, al-

ternate cells being arranged with the tablet II uppermost and the othercells with the carbon layer I6 uppermost. 'I'he size of theprotuberances I2 is such that they can protrude through the perforationsI9 or I9. The strip I'I may be formed of rubber or a synthetic rubbercompound in which case over the entire surface of the strip II to whichthe cells are applied a coating of adhesive is provided. The upperportion of the strip I'I shown in Figure 1 is folded or wrapped over theexposed surfaces of the cells by folding said gportion along the dottedline 29, the perforations I8 registering with the protuberances I2. Thelower portion of the strip I'I is then folded along the dotted line 2|and arranged to overlap the edge of the upper portion of the strip I1 asshown in Figures 2 and 3. The opposite POI- tions of the strip I1extending between the adjacent edges of the cells are now pressedtogether as shown at I'Ia in Figure 4. n Since the strip I 'I is coatedwith adhesive, the portions of the strip I 1 between the adjacent cellswill adhere and likewise the overlapping edges. The strip I1 will alsoadhere to the surfaces of the tablet II and the carbon layer I9 withwhich it engages. If desired the strip I'I may be formed ofthermoplastic sheet material or bitumen coated paper in which case theportions of the strip shown at I'Ia can be caused to adhere, without theaid of a separately applied coating of adhesive, on the application ofheat and pressure. Preferably a space is left between the strip I 'I andthe edges of the cells so as to permit breathing of the cells when inuse and if desired the strip I'I may be appropriately fluted wherenecessary to permit the required space to be left. The cells are thusenclosed in separate compartments formed by the strip I1, opposite facesof each cell being, however, exposed through the perforations I8 and I9.The folding or wrapping operation and the pressure and heat if necessarywhich ls applied to cause opposite portions of the strip betweenadjacent groups to adhere can be effected mechanically, the requiredoperations. together with the feeding of the cells to the strip I1 beingeffected in proper sequence. By sheathing the cells in the above mannerit is possible to manufacture the sheathed cells in a continuous manner,the requisite number of cells to provide a battery of predeterminedvoltage being severed as required. To assemble the sheathed cells toform a battery the strip I1 is folded at the portions Ila so that thesheathing and the cells assume a zigzag formation as shown in Figure 5with the appropriate surfaces of the cell elements facing one another.'I'his folding operation can also be effected mechanically. To completethe assembly, conducting plates 22 and 23 are applied to the end cellsas shown in Figure v5, these plates having lugs 24 and 25 which form theterminals of the battery. A portion of the strip I1 preferably extendsover the outer surfaces of the plates 22 and 23, as shown at Ilb and IIcin Figure 5., and on each end of the battery plates 26 and 21 ofinsulating material are applied. Suitable pressure is now applied to thestack to cause the surfaces of the cell elements exposed through theperforations I3 and I9 firmly to engage one another and to cause theportions of the strip I'I bounding the apertures I8 and I9 to be pressedinto firm contact with the sides of the cells. Whilst in the compressedcondition the stack is bound together by a strip of adhesive coatedpaper 23, as shown in Figure 6. Instead of using a paper strip 29 thestack may be bound with thread. The stack is then provided with anexterior coating of wax, bitumen or rubber, in any suitable manner. Itwill thus be appreciated that by manufacturing batteries in the mannerdescribed the necessity for separately sheathed cells is avoided sofacilitating manufacture. By sheathing the group of cell elements in themanner described, an effective seal is provided which prevents orsubstantially reduces the escape of electrolyte from one cell to anotherin the assembled battery.

Figures 7, 8 and 9 of the drawings illustrate a modified form of theinvention in which the cells are more widely spaced on the strip I'Icompared with the spacing shown in Figure 1 so as to provide asufficient length of material I'Id between the adjacent cells to enablesaid length IId whenv the cells are caused to assume their zigzagformation to lie between adjacent cells, as shown in Figure 9. In thisformation of the invention the perforations I8 and I9 are of course morewidely spaced than the perforations I8 and I9 of Figure 1 and to providecontact between adjacent cells the length I Id is also perforated at.29,as shown in Figure 8, these perforations being preferably provided afterthe material between adjacent cells has been caused to adhere. In thisembodiment either the tablets II or the -carbon layers are uppermost sothat these elements do not alternate as in the embodiment of Figure 1.

Figure 10 of the drawings illustrates a further embodiment of theinvention in which the depolarising tablet II and the gauze pad I3 arearranged in one compartment and the carbonzinc element I5, I6 isarranged in another compartment. As stated above other methods ofassembling the cell elements may be employed, for example, only theelements II and I3 need be arranged in said separate compartments andduring folding of the elements I I and I3 to their vzigzag formation thecarbon-zinc elements may be interposed between the wrapped elements IIand I3. A I

If desired, the carbon-zinc element may be of of a dished form so thatits edges can enclose the edges of the other elements of the cell asindicated in Figure 11. Further, if desired instead of folding thesheathed elements so that they assume the zigzag formation aforesaid, arow of sheathed elements in the condition shown in Figure 4 or 8 may beplaced face-to-face with one or more other rows of sheathed elements toform a battery as indicated in Figure 12. Further, a. long row ofsheathed elements may be folded to assume a zigzag formation but eachlimb of the formation may include a plurality of said compartments asindicated in Figure 13.

Instead of using a single strip I1 as above described to provide acommon sheath for a plurality of cell elements or groups as aforesaid,two strips A and B may be used as indicated in Figure 14, each striphaving recesses along its longitudinal edges, said strips being appliedto the cell elements or groups in such a manner that the longitudinalmargins of the said strips overlap over an area extending to each sideof a line passing through the centre of the row of cell elements shownin Figure 1, the recesses on one strip registering with the recesses onthe other strip so as to provide perforations on both faces of the cellelements or groups as shown in Figure 3. Thereafter the oppositeportions are secured together as at Ila and the battery assembled asabove described.

What I claim is:

1. An electric dry battery wherein a plurality of battery cells, eachcell including an electrolyte cell element, are arranged in a commonsheath of flexible electrolyte-resisting dielectric material, saidsheath being perforated and applied to said plurality of cells to formseparate compartments within which said cells are individually enclosedwith portions of the ijaces of said cells exposed through theperforations in said sheath, and means for'pressing said cell elementstogether, whereby said sheath at least reduces the escape of electrolytefrom `one cell to another whilst electrical contact between adjacentcells is obtained through said perforations.

2. A method of making an electric dry battery which comprises arrangingin a common perforated sheath of flexible electrolyte-.resistingdielectric material a plurality of battery cells. each cell containingan electrolyte cell element, forming said sheath with each of said cellsin a separate compartment with the faces of said cells exposed throughthe perforations in said sheath, folding said sheath to bring said cellsinto conductive relationship to form a battery of cells, and thensecuring said cells together under pressure.

3. A method of making an electric dry battery which'comprises enclosinga plurality of battery cells, each cell containing an electrolyte cellelement in a common perforated sheath of flexible electrolyte-resistingdielectric material with said cells arranged edge to edge but spacedapart with portions of the faces of said cells exposed throughperforations in said sheath, then securing the opposite surfaces of saidsheath together at the spaces between said cells to form separatecompartments within which said cells are individually enclosed, thenfolding said sheath to bring adjacent cells into electrical contact witheach other through the perforations in the sheath, and then securingsaid cells together under pressure.

4. A method according to claim 2, wherein said sheath is formed byfolding sheet material having edge recesses to bring the recessed edgestogether to provide the perforations.

5. A method of making an electric dry battery which comprises applyingin spaced relationship to a perforated strip of flexibleelectrolyte-resisting dielectric sheet material a plurality of batterycells, each cell containing an electrolyte cell element, with one faceof each of said elements exposed through a perforation in said strip,then folding said strip to overlap its longitudinal edges on theopposite faces of said elements and with said overlapped faces alsoexposed through perforations, then securing together opposite surfacesof said strip which lie between adjacent edges of said cells to encloseeach of said cells in a separate compartment, folding said strip tobring adjacent cells into electrical contact with each other through theperforations in the strip,

and then securing said cells together under pressure.

6. A method of making electric dry batteries in a continuous mannerwhich comprises arranging a plurality of battery cells, each containingan electrolyte cell element, in a common perforated sheath of flexibleelectrolyte-resisting dielectric material with each of said cells in aseparate compartment with the faces of said cells exposed throughperforations in said sheath, then severing a plurality of said cells ina common length of said sheath, and bringing each cell into electricalcontact with other cells through the sheath perforations to form abattery.

7. A method according to claim 3, wherein the cells are brought intocontact by folding the `sheath between adjacent cells to produce azigtic substance, and heat and pressure are applied UNITED STATESPATENTS to said opposite surfaces to secure them together. i

11. A method according to claim 2 wherein each Nzuggos schz'emJunepgt'elga cell includes a. depolarising agent in the form of 2'416079 Anthony Feb 18 1947 a tablet having a. protuberanceon one face pxo-5 truding through a perforation in said sheath. FORMGN PATENTS Y GEO. H.WILKINSON. Number Country Date A REFERENCES Crum 64" 985 Franc? us 61928 The following references are of record in the 1 le of this patent:

1. AN ELECTRIC DRY BATTERY WHEREIN A PLURALITY OF BATTERY CLEES, EACHCELL INCLUDING AN ELECTROLYTE CELL ELEMENT, ARE ARRANGED IN A COMMONSHEATH OF FLEXIBLE ELECTROLYTE-RESISITING DIELECTRIC MATERIAL, SAIDSHEATH BEING PERFORATED AND APPLIED TO SAID PLURALITY OF CELLS TO FORMSEPARATE COMPARTMENTS WITHIN WHICH SAID CELLS ARE INDIVIDUALLY ENCLOSEDWITH PORTIONS OF THE FACES OF SAID CELLS EXPOSED THROUGH THEPERFORMATIONS IN SAID SHEATH, AND MEANS FOR PRESSING SAID CELL ELEMENTSTOGETHER, WHEREBY SAID SHEATH AT LEAST REDUCES THE ESCAPE OF ELECTROLYTEFROM ONE CELL TO ANOTHER WHILST ELECTRICAL CONTACT BETWEEN ADJACENTCELLS IS OBTAINED THOUGH SAID PERFORATIONS.